Effectiveness of sphenopalatine ganglion block for V1 trigeminal neuralgia secondary to herpes zoster. case report

Abstract

Introduction: Postherpetic V1 branch trigeminal neuralgia (TN) is a different neuralgia of the maxillary and mandibular divisions. This is usually refractory to conventional management since the involvement of the ophthalmic division can produce obvious autonomic symptoms. Few cases have been described, and conventional therapy is usually ineffective. Multimodal analgesic approaches are required in which regional anesthesia is considered an option, in order to optimize the response and improve the patient's quality of life. Methodology: A clinical case of a previously healthy 43-year-old female with a history of facial Herpes Zoster is reported. She presents TN of the left unilateral ophthalmic division for six months of evolution. The characteristic pain is accompanied by autonomic manifestations, refractory to pharmacological treatment. A sphenopalatine ganglion (SPG) block was performed in the pterygopalatine fossa with an infracygomatic approach. The evolution of pain was recorded on the Numerical Visual Analog Scale (VAS) and the quality of life was reported by the Headache Impact Test (HIT-6) scale on days 1, 15, 30, and 90 after the procedure. It was correlated with what was reported in the literature, finding only three cases related to autonomic trigeminal neuralgia (TN), which were treated with radiofrequency. The strongest evidence lies in the use of sphenopalatine ganglion block, radiofrequency ablation, and neurostimulation for cluster headaches. Results: A decrease in pain was reported on the VAS scale from 10/10 to 0/10 after the procedure, which was maintained during the first month without presenting autonomic symptoms. In the third month, VAS 2/10 is recorded, which is accompanied by tears. According to the HIT-6 scale, there was an improvement in quality of life from 69 points (very severe impact) to 36 points (little or no impact). Discussion: In recent studies, the connection of the ophthalmic nerve with the SPG has been found, in such a way that it is a possible explanation of why the SPG block is effective for pain relief in the ophthalmic nerve area in patients with TN. Conclusion: The present case of TN V1, with SPG blockade, showed analgesic efficacy and improvement in the quality of life reported by the patient. Further research with larger cohorts is required to standardize the procedure for such a diagnosis.